Bolts from the Blue

Source: Weather.gov

One of the most dangerous types of cloud to ground lightning. The photo below is a classic example of 'Bolts from the Blue". These lightening bolts typically come out of the back side of the thunderstorm cloud, travel a relatively large distance in clear air away from the storm cloud, and then angle down and strike the ground. These lightning flashes have been documented to travel more than 25 miles away from the thunderstorm cloud. "Bolt from the Blue" lightning flashes are a very dangerous type of cloud to ground lightning flash, as they "appear" to come out of the clear sky.

This is why it is still dangerous to be outside when thunderstorms are in the region, the lightning can, and does, strike many miles away from the thunderstorm cloud itself. It is always a good idea to wait 30 minutes or more after the rain ends before resuming outdoor activities.